低氧胁迫下黄瓜幼苗根系多胺代谢的变化

 利用外源Spd、PAO 抑制剂研究了黄瓜幼苗根系在低氧水培时的生长状况以及内源PAs、H₂O₂ 含量和PAO活性的动态变化。结果表明, 外源PAs对低氧胁迫下黄瓜幼苗根系的生长有促进作用;低氧处理后3种PAs含量都明显上升, 外源Spd和PAO抑制剂增加了根系中的PAs含量, 降低了根系中H₂O₂ 含量, 减缓了低氧伤害; PAs为低氧胁迫的应激产物, PAO为适应酶类, 其活性随PAs含量的变化而发生变化。     

苹果新根内源多胺周年形成动态研究

研究了苹果吸收根和延长根内多胺（精胺、亚精胺、腐胺）的周年形成动态。结果表明，两类新根中多胺总量１年内均有３次明显的形成高峰，分别出现在４月初、６月上和９月初；５－７月３种多胺变化最频繁；亚精胺和腐胺含量在两种根内均有４次高峰，吸收根内精胺含量有５个峰，延长根中有３个峰，两种新根内精胺含量最高，变化也最大。     

‘新高’梨花粉败育与内源多胺含量变化的关系

 以花粉败育的‘新高’梨和花粉可育的‘丰水’梨为试材, 对不同发育阶段的花蕾或花药内不同形态的腐胺( Put) 、亚精胺( Spd) 和精胺( Spm) 含量进行了分析, 以探讨多胺种类和形态与新高花粉败育的关系。结果表明: 新高花蕾发育过程中游离态的Put和Spd含量变化幅度不大, 丰水则在单核花粉到二核花粉时期出现高峰, 在单核花粉期到单核花粉晚期含量是新高的3～5倍。新高中游离态的Spm也显著低于丰水; 丰水中高氯酸可溶共价结合态Put、Spd和Spm含量逐渐增加, 新高在花粉败育前期或败育期出现不同于丰水的高峰; 除丰水成熟的花药外, 两个品种中高氯酸不溶结合态多胺含量的变化基本一致; 两个品种的不同形态Put、Spd和Spm总量在败育前期差异不显著, 此后新高显著低于丰水; 丰水中的多胺均以游离态为主, 新高以高氯酸可溶结合态为主。     

Protective role of ornithine decarboxylase (ODC)/polyamines system in the myocardium induced by ischemic preconditioning in rats

AIM: To explore the protective role of ornithine decarboxylase (ODC)/polyamines system in the myocardium induced by ischemic preconditioning in rats.METHODS: The experiment model of simulating myocardial ischemia-reperfusion was replicated by Langendorff perfused rat heart. The hearts were randomly divided into six groups: control group, ischemic-reperfusion group (IR), weak ischemic preconditioning group (IPCw), strong ischemic preconditioning groups (IPCs) and inhibitor groups (DF-EG-IPCw and DF-EG-IPCs). The expression of ODC was quantified by Western blotting analysis. The contents of polyamines (putrescine, spermidine, spermine) in cardiac tissue were detected with high performance liquid chromatography. The hemodynamics was obtained using the PowerLab 8/SP TM data acquisition system. The infarct size was measured using triphenyltetrazolium chloride (TTC) staining and the apoptosis cardiomyocytes were observed under optic microscope after TUNEL method treatment. RESULTS: In contrast with control group, in IR group the putrescine contents increased, the expression of ODC was down-regulated, the contents of spermine and the total polyamine pool decreased (P<0.05). At the same time, the cardiac function declined, with an increase in myocardium infarct size and the apoptosis rate of cardiomyocytes (P<0.05). When compared with IR group in terms of LVDP, HR and CF, both IPCw and IPCs groups had significant improvements in cardiac functions (P<0.05). These two groups also had smaller myocardium infarct size (P<0.01) and apoptosis rate of cardiomyocytes (P<0.01). When compared with IR group, the expression of ODC, the contents of spermine and the total polyamine pool increased in both IPCw (P<0.05) and IPCs groups (P<0.01), but the putrescine contents declined. In the respective inhibitor groups of the weak and ischemic preconditioning, the expression of ODC and the levels of putrescine, spermidine, spermine and the total polyamine pool decreased remarkably (DF-EG-IPCw vs IPCw, P<0.05; DF-EG-IPCs vs IPCs, P<0.01), while the myocardium infarct size and apoptosis rate of cardiomyocyte were relatively bigger in both inhibitor groups (P<0.05). Also, the heart function decreased significantly in terms of LVDP, HR and CF compared to their matched ischemic preconditioning group (P<0.05).CONCLUSION: Ischemic preconditioning significantly up-regulates the ODC / polyamines system in Langendorff perfused rat hearts and provides protective effects on myocardium with ischemia/reperfusion injury. Inhibition of bio-synthesis of polyamine abolishes the cardiac function improvement and the decreases the infarct size and apoptosis rate induced by ischemic preconditioning. It reveals that the ornithine decarboxylase (ODC) /polyamines system may be involved in the protection of myocardium induced by IPC in rats.     

石竹花芽发生与内源多胺含量的关系

以石竹叶片为外植体,诱导愈伤组织、营养芽、花芽的培养基分别为ＭＳ＋ＺＴ２．５ｍｇ／Ｌ＋２,４－Ｄ０．３ｍｇ／Ｌ;ＭＳ＋ＺＴ１ｍｇ／Ｌ＋ＢＡ２ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ;ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ＋ＮＡＡ０．３ｍｇ／Ｌ。在石竹离体叶花芽形成过程中,内源多胺含量呈不同的变化趋势,腐胺、亚精胺含量上升,而二丙胺、精胺含量下降,表明多胺与石竹离体叶花芽分化有明显的内在联系。     

Effects of exercise training on myocardial polyamine metabolism in aged rats

AIM:To explore the effects of exercise training on myocardial polyamine metabolism in aged rats. METHODS:Wistar rats were divided into 3 groups:old+exercise group(Old+Ex), old group(Old) and young group(Young). High-performance liquid chromatography was used to test the content of myocardial polyamines(putrescine, spermidine and spermine). The activity of polyamine synthesis and catabolism rate-limiting enzyme ornithine decarboxylase(ODC) and spermidine/spermine acetyltransferase(SSAT) was analyzed by [¹⁴C] labeling. The level of malondialdehyde(MDA) and the activity of superoxide dismutase(SOD) in the myocardium were detected by colorimetric method. The levels of TNF-α and IL-1β were determined by enzyme-linked immunosorbent assay. The cardiac functions were measured by echocardiography. The changes of myocardial ultrastructure were observed under transmission electron microscope. RESULTS:(1) Compared with Young group, ODC activity decreased, SSAT activity increased, and the levels of spermidine, spermine and total polyamine were significantly decreased in Old group. SOD activity also decreased significantly, the content of MDA, TNF-α and IL-1β also increased dramatically in Old group. In the old rats, both left ventricular end-systolic diameter(LVESD) and end-diastolic diameter(LVEDD) increased, while left ventricular ejection fraction(LVEF) and fractional shortening(LVFS) decreased.(2) Compared with Old group, ODC activity increased, SSAT activity decreased, the levels of spermidine and total polyamine significantly increased, SOD activity increased significantly, and the content of MDA, TNF-α and IL-1β decreased dramatically in Old+Ex group. The functions of left ventricle also improved significantly in Old+Ex group.(3) Ultrastructural observations indicated that the myofilament and mitochondrial cristae were irregular and mitochondrial matrix density decreased in old rat heart. The cardiac sarcomere structure was clear, the mitochondrial matrix was dense and the mitochondrial cristae arranged in order in Old+Ex group. CONCLUSION:Exercise training promotes polyamine synthesis metabolism and inhibits polyamine catabolism in the heart of aged rats, thus fighting against aging-induced myocardial polyamine decrease. Exercise training also improves the capacity of anti-inflammatory and antioxidant processes of aged heart. Maintaining the appropriate levels of myocardial polyamines may be a new mechanism to delay cardiac aging.     

Effect of various polyamines on production of protocorm-like bodies in orchid—Dendrobium ‘Sonia’

Polyamines, putrescine, spermidine and spermine all at three concentrations viz., 0.2, 0.4 and 1.0 mM were tested, by supplementing to MS basal+4.44 μm BAP medium. The explant used was fractionated plb. Ethylene and methane was measured at 20 and 40 days after inoculation (DAI). Among various polyamines tested, maximum number of plb’s (protocorm-like bodies) were produced in putrescine 0.4 mM treatment. Increase (1.0 mM) or decrease (0.2 mM) in concentration caused a decrease in the production of plb’s. All spermidine and spermine treatments resulted in the production of less number of plb’s than control. No ethylene evolution was observed in any of the polyamine treatments. However, methane evolution was observed in all the polyamine treatments. The absolute amounts, of methane evolved could not be related to the observed plb’s production response. However, when the evolution of methane was more than 1 nmol per gram FW h⁻¹, poor plb’s production was observed.     

Relationship between changes in endogenous polyamines and seed quality during development of sh2 sweet corn (Zea mays L.) seed

Polyamines putatively affect tolerance to abiotic stresses and are believed to be important in organogenesis. Present experiments investigate the relationship between polyamines (PAs) and seed quality. Therefore, during seed development, the changes in free putrescine (Put), spermidine (Spd) and spermine (Spm) and physiological and biochemical parameters in F₁ seeds of sh₂ sweet corn were compared. Concentrations of Put, Spd and Spm increased from 14 to 30 days after pollination (DAP). After 30 DAP Put concentration declined with an opposite trend to that of Spd and Spm. The regression analysis between PAs and seed quality described by physiological and biochemical parameters including germination percentage, germination energy, germination index, seed size, seed fresh and dry weight, total soluble sugar, total soluble protein, Malondialdehyde (MDA) concentration, electrolyte leakage, peroxidase (POD) and catalase (CAT) activity were conducted. Spd was observed to have a closer relation with the comprehensive physiological changes of seeds during their development than that of Put and Spm. Moreover, the Spm concentration might be more suitable to forecast seed germinability during seed maturation period than Spd and Put. It indicated that endogenous Spd and Spm in dissociated form had more effect than Put during seed development progress of sweet corn.     

鸭梨,茌梨果实采前乙烯生物合成特性研究

鸭梨、茌梨果实均从盛花后１４５天进入呼吸跃变，同时伴随着乙烯释放高峰的出现。鸭梨的乙烯合成酶（ＥＦＥ）活性和氨基环丙烷羧酸（ＡＣＣ）含量高于茌梨，乙烯释放量的峰值是茌梨的４倍，两品种果实的ＥＦＥ活性变化与果实的呼吸跃变和乙烯释放量的变化同步，ＡＣＣ含量自盛花后１３５天，一直呈止升趋势。两品种果实内含有亚精胺、腐胺和精胺三种内源多胺，亚精胺与梨果实乙烯生物合成有关。     

Effect of polyamine on cardiac hypertrophy induced by isoproterenol in rats

AIM: To investigate the effect of polyamine, ornithine decarboxylase（ODC）and spermidine/spermine N1-acetyltransferase (SSAT) cardiac hypertrophy induced by isoproterenol (ISO) in rats. METHODS: Cardiac hypertrophy in rats was induced by subcutaneous administration of isoproterenol. High performance liquid chromatography was used to measure the concentrations of polyamines. RT-PCR and Western blotting were used to determine the mRNA and protein expressions of ODC and SSAT during different time points. RESULTS: Compared with control group, heart weight index was increased markedly at ISO 7 d. The concentration of putrescine was increased at ISO 1 d (P<0.05) and increased significantly at 5d and 7 d (P<0.01). The concentration of spermidine was increased at 3 d and increased significantly at 7 d. The concentration of spermine was increased and total pool of polyamine was increased significantly. The expression of ODC and SSAT mRNA were upregulated at 1 d (P<0.05) and kept on high level (P<0.01). The expressions of ODC and SSAT protein were upregulated at 1 d and 5 d (P<0.05) and the changes were significant at 7 d (P<0.01). CONCLUSION: These results indicate that increased polyamine and the upregulated expression of ODC and SSAT in rat cardiac tissue may take part in the process of cardiac hypertrophy induced by isoproterenol.     

低温胁迫下4种苹果砧木叶片多胺的变化

以山定子(Malus baccata Borkh)、新疆野苹果[M.sieversii(Ledeb)Roem]、烟台沙果[M.prunifoli(Willd)Borkh]和莱芜难咽(M.micromalus Makino)等4种苹果砧木为试材,测定了低温胁迫下不同砧木叶片的多胺含量。结果表明,胁迫6 h时叶片的MDA含量可反映4个砧木的耐寒性,从高到低依次为山定子>新疆野苹果>莱芜难咽>烟台沙果;低温胁迫能明显诱导多胺总量(PAs)、腐胺(Put)、亚精胺(Spd)和精胺(Spm)的合成,耐寒性强的山定子和新疆野苹果PAs、Put和Spd增加显著,而耐寒性较弱的莱芜难咽和烟台沙果多胺和3种胺的变化不大。低温胁迫6 h时,MDA变化量与叶片PAs、Put、Spd变化量以及Put/PAs比值呈极显著或显著负相关,而与(Spd+Spm)/Put、Spd/PAs、Spm/PAs呈显著正相关,与Spm变化量无相关关系,表明当低温胁迫下叶片PAs、Put、Spd增加量较大时,苹果砧木耐低温胁迫的能力比较强,PAs、Put及Spd在胁迫条件下的增加量可作为苹果砧木耐低温胁迫能力高低的鉴定指标。     

Endogenous and exogenous polyamines in the organogenesis in Curcuma longa L.

The present work evaluated the development of different Curcuma longa L. explants (leaves basis, root tips and ancillary buds from rhizome) stimulated by exogenous polyamines, combined with naphtalen-acetic acid (NAA) or with 6-benzyl-aminopurine (BAP), to produce callus and its subsequent differentiation. The explants, isolated from field plants, were previously subjected to a basic cleaning method and were inoculated onto Murashige and Skoog culture medium (MS) [Murashige, T.S., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiologia Plantarum 15, 473–497] supplemented with NAA (2.0 mg L⁻¹). Buds were subjected to different treatments, with or without 5.0 and 10.0 mmol L⁻¹ exogenous polyamines (mixture of putrescine:spermine:spermidine, 1:1:1) combined with NAA. The calluses obtained were transferred into the same medium, supplemented with the mixture of polyamines combined with BAP, in order to induce plant differentiation. For C. longa, buds were the most efficient explants for callus induction (p < 0.05). The application of exogenous polyamines (5.0 and 10.0 mmol L⁻¹) produced the most developed callus, with numerous roots. The medium supplemented with 10 mmol L⁻¹ polyamine mixture, combined with BAP, induced good regeneration, producing vigorous plants and excellent shoot formation.Polyamines addition promoted the formation of callus, roots and leaves, representing an important factor in the determination of indirect organogenesis in C. longa L., and putrescine content may be considered a valuable marker of the differentiation process in this specie, as well as the enzyme peroxidase.     

外源水杨酸对鸭梨叶片内源多胺含量的影响

以鸭梨为试材,研究了外源水杨酸对叶片内源多胺含量变化的影响.结果表明:不同浓度水杨酸处理对多胺含量变化的影响不同,低浓度的水杨酸处理在一定的时间内提高了叶片内源多胺的含量,而高浓度的水杨酸则抑制内源多胺的合成.在田间试验中,5月26日至7月26日腐胺和亚精胺含量显著提高,精胺含量无显著变化.     

多胺及其合成抑制剂对梨花粉萌发及花粉管生长的影响

以丰水梨为材料,采集开花前1d或当天花蕾的花粉,进行离体培养。结果表明,精胺、亚精胺和腐胺在低浓度时均能促进离体花粉萌发和花粉管生长,但超过一定浓度时则对其起抑制作用。精胺、亚精胺和腐胺促进花粉萌发及花粉管生长的适宜浓度分别为0.005～0.025mmol/L、0.05～0.25mmol/L和0.05～0.25mmol/L。多胺的合成抑制剂甲基乙二醛-双-鸟苷基腙(MGBG)能抑制离体花粉萌发和花粉管生长。     

NaCl胁迫对番茄嫁接苗根系多胺含量的影响

以耐盐番茄品种‘影武者’为砧木, ‘宝大903’为接穗, 研究了100 mmol·L^-1NaCl胁迫10 d条件下, 嫁接苗与自根苗生长和根系不同形态(游离态、结合态和束缚态) 多胺含量的变化。结果表明: 嫁接苗的生物量显著高于自根苗; 在整个胁迫期内嫁接苗根系3种形态的腐胺和精胺含量呈上升趋势,3种形态的亚精胺含量呈下降趋势; 自根苗根系游离态和结合态精胺含量在胁迫第6天达到峰值后下降;束缚态精胺含量变化不明显, 3种形态的腐胺、亚精胺含量在整个胁迫期内呈下降趋势。以上结果表明,腐胺和精胺在番茄嫁接苗根系耐盐性方面发挥着重要作用。     

高温胁迫下耐热性不同番茄多胺水平变化的差异

 研究了高温条件下番茄4个耐热和2个不耐热品种体内腐胺、精胺和亚精胺水平变化的差异。结果表明，在苗期和开花期，不耐热品种叶片和花器官中精胺和亚精胺含量在昼/夜温度33/25 ℃下显著高于对照(25/20 ℃)，38/28 ℃下显著低于对照；耐热品种都随温度升高而升高,38/28 ℃时最高。在25/20 ℃ 、33/25 ℃下，不耐热品种的精胺和亚精胺含量与耐热品种相当或者高于耐热品种，在38/28 ℃高温下耐热品种显著高于不耐热品种。所有参试番茄品种在不同温度处理中腐胺含量的变化没有明显的规律性。     

柑桔果实采后某些生理变化与多胺的关系

对锦橙、脐橙、peng柑贮藏期多胺、呼吸强度、营养物质（糖、酸、有机酸、维生素C）、果皮电导率、枯水发生情况进行了观测。结果表明,3个品种果实在后期衰老过程中,Spm、Spd含量相对降低,而Put含量相对提高。3个品种果实衰老过程中,糖、有机酸、维生素C含量逐渐降低,与Spm、Spd含量变化成正比,与Put含量变化成反比。锦橙、脐橙在后期衰老过程中,呼吸强度逐渐降低,与Spm、Spd含量变化成正比,与Put含量变化成反比;而peng柑这段时期呼吸强度逐渐提高,与Spm、Spd含量变化成反比,与Put含量变化成正比。3个品种果实在衰老后期果皮浸泡液电导率提高,果皮细胞渗性与Spm、Spd含量变化成反比,与Put含量变化成正比。     

Ameliorative effect of polyamines on the high temperature inhibition of in vitro pollen germination in tomato (Lycopersicon esculentum Mill.)

Effect of polyamines on in vitro pollen germination at high temperatures in tomato (Lycopersicon esculentum Mill.) was investigated. Pollen germination and tube growth were significantly inhibited at 33°C and 35°C compared to those at 25°C. This inhibition was reversed by the addition of spermidine or spermine in the germination medium. Spermidine at 0.5 mM was slightly more effective than spermine at 0.05 mM. Spermidine at 0.05 and 0.5 mM and spermine at 0.05 mM slightly increased pollen germination rates at 25°C. Spermidine at 5 mM and spermine at 0.5 M were inhibitory to pollen germination, regardless of incubation temperatures. Spermidine also promoted germination of pollen grains incubated at 38°C for 1 and 3 h and then at 25°C for the rest of the 20 h incubation period. The effect was higher at 0.5 mM than at 0.05 mM. Treatment of spermidine to intact flowers 1 day before anthesis was also effective in ameliorating the high temperature inhibition of in vitro pollen germination on the polyamine-free medium. Here, the optimum concentration was 5 mM. These results demonstrate that polyamines can counteract the inhibitory effects of high temperature on pollen germination. They also suggest that the endogenous level of polyamines in germinating pollen grains is an important factor for the pollen germinability at high temperature.     

Exogenous polyamines alleviate the lipid peroxidation induced by cadmium chloride stress in Malus hupehensis Rehd.

In order to investigate the effects of spermidine (Spd) and spermine (Spm) on the stress of cadmium chloride (CdCl₂), it was checked that the content of polyamines and malondialdehyde (MDA), the rate of superoxide anion (O₂⁻) generation and the activities of superoxidase dismutase (SOD) and guaiacol peroxidase (GPX) in 1-year-old Malus hupehensis Rehd. var. pinyiensis Jiang (tea crabapple) seedlings grown in nutrient solution. The result showed that the content of free putrescine (Put) was increased, the contents of free Spd and Spm and the (Spd + Spm)/Put ratio in leaves were decreased significantly under CdCl₂ treatment. Foliar spraying with Spd or Spm under CdCl₂ treatment, the accumulation of free Put reduced, the contents of free Spd and Spm and the ratio of (Spd + Spm)/Put in leaves increased significantly. The activities of SOD and GPX in leaves were enhanced and O₂⁻ generation rate and MDA content were decreased significantly by foliar spraying with Spd or Spm under CdCl₂ treatment. Results suggest that both Spd and Spm can alleviate the lipid peroxidation caused by CdCl₂ in M. hupehensis var. pinyiensis.     

Biochemical changes in dormant grapevine shoot tissues in response to chilling: Possible role in dormancy release

At leaf fall, one-year-old shoots of cv. Superior Seedless table grape were collected and cut into single-node sections. These cuttings were subjected to 0, 100, 200, 300, 400 or 500 h of chilling at 5 °C to simulate natural chilling accumulation. After each treatment, one group of cuttings was forced to break buds while a second group was used to study biochemical changes taking place in the bud and underlying internode tissues. Carbohydrates, free polyamines and proline concentrations were determined and amylolitic and invertase (EC 3.2.1.26) activities were estimated. Low temperature treatment caused a hydrolysis of starch concomitant with an accumulation of sucrose. There was also a rapid build-up of proline, putrescine (Put) and spermidine (Spd) which reached their maximum levels at 300 positive chill units (PCU). Afterwards, as buds approached chilling satisfaction (400 and 500 PCU), hexoses accumulated in the buds while sucrose concentration increased considerably in both structures. Proline and Put, however, decreased in both tissues. Spd level remained high, while spermine (Spm) increased slightly. Changes in starch concentration seem to be controlled by α-amylase (EC 3.2.1.1). Sucrolytic activity, consisting mainly in the acid invertase form, changed inversely to sucrose concentrations. Nevertheless, at chilling satisfaction both sucrose content and invertase activity remained high in the buds implying a possible import of sucrose into the bud which acted as a strong utilizing sink. Our data suggest that limited budbreak due to a lack of chilling may be due to low hexoses availability. However, as buds approached chilling satisfaction, a high acid invertase activity, high soluble sugars concentration and a decrease in Put to Spd plus Spm ratio appear to be correlated with bud dormancy release and improve budbreak. Furthermore, endodormancy can be divided into two phases: the first one (from 0 to 300 PCU) is an acclimation period; the second (from 300 to 500 PCU) is a beginning of growth resumption.